All cell cast acrylic constructionClear lid to view proper O-ring sealKey hole slot for lid removalMicro ball valve effluent controlEheim 1048 pump, bolted to base platepH probe port in lidpH probe adapter includedAuto fill bubble counter9 x 10 foot print, 18" overall heightHolds 8 pounds of media, we recommend large grain schuran typeFor reef aquariums up to 300 gallonsThe world famous GEO calcium reactor! GEO reactors are fabricated using only the finest cast acrylic materials and high quality fittings. Designed with the user in mind, we feel these are by far the easiest reactors on the market to install, operate and maintain. Bottom up flow of water captures free CO2 and draws it back into the pump. This means less gas in the reactor and less gas in the effluent. There is no need for a second single pass chamber with our design. These reactors include all of the fittings and tube required for normal installation. The user will need to supply the media, CO2 equipment and feed pump.